Steps to reproduce
Install Magento 2.2.X CE Sample Data Admin > Stores > Configuration > Catalog > Inventory > Stock Options > Display Out of Stock Products = Yes.
CLI php bin/magento indexer:reindex
Admin > Products > Catalog > Create configurable product with 1 attribute. Set either Quantity = 0 or Stock Status = Out of Stock.
Frontend product should display with all Simple products part of Configurable product and should display with class disabled (red strike through) for out of stock .
Frontend product not displayed all.